1. Field of the Invention
The present invention relates to a lock unit comprising at least a catch, a first pawl having a pawl rotation axis, and a blocking lever, wherein in a locked state, the catch of the lock unit transfers a pivoting moment onto the first pawl and wherein the first pawl is fixed by means of a blocking lever. Lock units of this type are used in particular in motor vehicles for the purpose of locking doors, tailgates, or similar.
2. Brief Description of the Invention
In lock units described herein, the relative position between the catch and the pawl is not designed in such a way that the force exercised by the catch runs through the pawl rotation axis and consequently allows for an automatic fixation of the catch by means of the pawl. Instead, in order to provide a particularly quietly-operating lock unit, the pawl is in this case designed or arranged in such a way that the force exerted by the catch produces a turning moment for the pawl, facilitating the release of the catch. To this extent, the catch produces an opening moment for the first pawl so that said pawl can be easily moved into the opened position as a result of the spring-loading of the catch.
Equally, in order to guarantee a lasting locked state, provided is a blocking lever for fixing the first pawl in the locking position so that in particular, displacements of position in relation to the locking mechanism (for instance by compressing the door seals, the driving operation or similar) do not cause the lock unit to open or the contact between pawl and catch to be interrupted. In this way is the “self-opening” of the locking mechanism prevented.
Also in view of the increased number of parts used by such a locking system, a reliable operation of the complex sequence of movements in all operating conditions is desirable, whilst at the same time a compact design and a silently-operating locking system are of utmost importance.
It is one objective of the invention to at least partially solve the problems described with reference to the state of the art. In particular, the invention aims to provide a lock unit with a self-opening mechanism that still offers a compact and simple design.
These objectives are solved by a lock unit according to the characteristics of claim 1. Further advantageous embodiments of the lock unit and its preferred area of application are apparent from the dependent claims. It must be pointed out that the characteristics individually listed in the claims can be combined in any technologically sensible manner and illustrate further embodiments of the invention. Furthermore, the description, in particular with reference to the figures, explains further advantages and preferred embodiments of the invention.
The lock unit of the invention comprises at least a catch, a first pawl having a pawl rotation axis, and a blocking lever. In the locked state of the lock unit, the catch transfers a pivoting moment onto the first pawl and the first pawl is fixed by the blocking lever. Furthermore, a second pawl is provided, which is mounted on the pawl rotation axis and which can be engaged with the blocking lever and the catch.
The lock unit is in particular a lock for a motor vehicle door, although the lock unit can generally also be used in other doors, tailgates, etc. The function of the so-called locking mechanism—comprising a catch and a pawl—in motor vehicle locks is generally known, so that at this point it is only mentioned that a catch bolt is accommodated via the (spring-loaded) catch and fixed in a locked state. In order to stop the rotation of the catch, said catch bolt comprises a so-called intermediate-closed stop on its outer profile with which a respective elevation of the first pawl engages. For this purpose, the pawl carries out a rotary movement and then forms a contact area with the catch as the catch and pawl abut against each other.
In the locked state, the catch pushes onto a contact point (or small contact area) of the first pawl so that a moderate or ideal contact force vector is created. The contact force vector generally has a length (essentially corresponding to the amount of the force) and a direction into which the force (from the catch towards the first pawl) is exerted. In the “self-opening” mechanism this contact force vector does not point from the contact point towards the pawl rotation axis, but instead the contact force vector is arranged at an angle to said axis. This causes a pivoting moment in relation to the first pawl to be generated via the catch, the catch pushing the first pawl into the open position. In order to generate such an angled contact force vector, the contact surfaces between the first pawl and the catch around the area of the contact point and/or the position of both components may, in particular, be adapted in relation to each other. By using such an arrangement of the contact force vector, a particularly-smooth and thus also a silent operation of the pawl can be achieved during the opening of the locking mechanism.
In order to prevent the self-opening of the mechanism, a blocking lever is provided. Said lever is, in particular, positioned in such a way that it abuts against the first pawl and generates a blocking force counteracting the pivoting moment. In the locked state of the lock unit, the first pawl rests, for instance, against the fully-closed stop of the catch with the blocking lever being positioned on the side of the first pawl facing the catch. This blocking lever is, in particular, arranged pivotably and blocks the opening position of the first pawl in the locked state.
In order to achieve simple movement sequences and a compact design, in addition to the first pawl, a second pawl is provided, the second pawl being arranged on the same pawl rotation axis as the first pawl. The first and the second pawls can be moved independently from each other around the pawl rotation axis, at least within a (limited) area of rotation (e.g., from 10° to 60°). The second pawl can then on the one hand engage the blocking lever and on the other hand engage the catch. Thus, the second pawl carries out a double function (offset in time or delimited from each other), that is to say, acting on the one hand as a “normal” pawl in relation to the catch and, in addition, as a triggering lever for the blocking lever so that in the locked state of the catch, the first pawl and the blocking lever are disconnected from one another by the second pawl, which can be brought into contact with the blocking lever.
Particularly advantageous is an embodiment in which the catch comprises a fully-closed stop and an intermediate-closed stop, and in which the first pawl can engage with the fully-closed stop and the second pawl can engage with the intermediate-closed stop. In other words, this means, in particular, that the second pawl (with the first pawl engaged in the fully-closed stop of the catch) acts as a triggering mechanism for the blocking lever. Furthermore, the second pawl can also operate as a pawl in another state (offset in time) of the lock unit or of the locking mechanism by said pawl arresting (on its own) the catch in or at the intermediate-closed stop. This allows the option of designing the catch with a less complex form because due to the relative movement of the two pawls, different target points for a contact with the pawl or the catch can be provided.
According to a further embodiment of the lock unit, it is suggested that the second pawl comprises a release arm with a release journal which at times can be made to abut against a link of the blocking lever. This illustrates that the pawl does not only form a lever extending along an axis but also a release arm particularly extending at an angle from said lever. The release arm comprises at least a release journal extending, in particular, vertically to the pawl plane to cooperate, for instance, with a blocking lever arranged below or parallel to said plane. The blocking lever and the second pawl are now actually arranged in such a way that the release journal can at times cooperate with the connecting link of the blocking lever during pivoting of the second pawl, and in particular in a predefined pivoting area. It is preferred that the release journal is in contact with the link at the exact point in time when the first pawl is to be released. For this purpose a pivoting of the blocking lever against its frictional force towards the first pawl and a spring tensioning force is produced by means of the second pawl.
According to a further embodiment of the lock unit, the second pawl contains a blocking arm with a seat that can at times abut against the catch. This blocking arm serves in particular to interact with the catch in the area of the so-called intermediate-closed stop. Where the catch features a bolt extending from the plane of the catch, the face of the blocking arm forms a respective recess. Preferably a contact force acts in this case between the catch and the second pawl extending through the pawl rotation axis. Consequently, this suggests a non-self-opening mechanism.
The second pawl can also contain an operating arm connected to an operating lever. The operating lever thus serves, in particular, as a target point for the operating lever extending out of a housing of the lock unit and cooperating directly or indirectly with the actuation devices on the door or tailgate (e.g., a so-called internal operating lever and/or external operating lever). Such an operating lever can be designed as a rod assembly and/or a Bowden cable. Preferably, the operating arm of the second pawl is positioned on a side opposite to the release arm or blocking arm in relation to the pawl rotation axis.
In a particularly preferred embodiment, the second pawl contains a separate release arm, a separate blocking arm, and a separate operating arm. Such a second pawl is, in particular, designed as a flat molded part and is made, in particular, of metal and/or plastic.
It is also advantageous that means for limiting the relative pivoting movement is provided between the first and second pawl. Such means for limiting the relative pivoting movement has primarily the task of ensuring reliable unlocking even in a circumstance when the self-opening mechanism for ejecting the first pawl does not function. For this purpose it is particularly preferred that the first pawl and the second pawl are pivoted in the same direction around the pawl rotation axis during the opening operation so that the second pawl pivots the blocking lever during a first displacement phase and later (preferably offset in time) the second pawl pivots the first pawl (in particular where necessary, when the catch does not change the position of the first pawl).
Finally, also a motor vehicle is suggested comprising at least one described lock unit according to the invention. Such a lock unit is intended in particular for locking doors and/or tailgates of such motor vehicles.